Steel spring spoke tire



STEEL SPRING SPOKE TIRE Filed April 7, 1342 2 Sheets-Sheet l STEEL SPRNG SPOKE TIRE 2 Sheets-Sheet Filed .April 7p 1942 Patented July 30, 1946 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to tires for road vehicles, aeroplanes and military vehicles and aims to produce a serviceable tire without the use of any rubber whatever in its composition.

The primary object is to obtain a light weight, resilient road contacting tire portion so spaced apart from the vehicle wheel that none of the wheel or vehicles loads can be impinged directly 'f nor severely upon the tread portion; this may well be called the first principle of tread durability for Without applying this principle early tread deterioration can be expected regardless of tread materials.

Another related object is to place the means I employ to obtain resiliency as near the wheel as possible, so that little flywheel action or gyroscopic force will result from high velocities of the tire, while never-the-less the actual resiliency itself will be available far outward where the tread portion of the tire exists.

A still further object is to provide a tire which readily attaches to the central part of the drop center rim of present auto wheels and one having ample lateral strength although made of comparatively cheap materials in order to permit American vehicles to operate at normal speeds and with great safety in spite of the war occasioned rubber shortage.

Other objects will appear as I proceed to describe the tire in relation to the several views of the drawings:

Fig. 1 shows my invention as applied to a conventional automobile wheel and rim; side elevation.

Fig. 2 is a view in section along the line 2-2 of Fig. l and showing in addition certain tape means of binding the cords together.

' Fig. 3 is a View partly in section taken along the line 3-3 of Fig. 2 and Fig. 4 is an enlarged view partly in section taken along the line 4--4 of Fig. 2.

Fig. 5 shows an alternative arrangement.

Proceeding with the more detailed description of my invention I shall employ like numerals to represent similar parts throughout the several views: ll indicates a typical automobile wheel, being the stamped spider thereof, while 2 indicates the drop center portion of a conventional inflated tire rim; the portions of such conventional rim which are not needed when employing my non-rubber tire have been out oli at the posi* tion indicated by 3, see Fig. 2.

To afford a firm foundation for my resilient non-rubber tire I insert hard wood or fibre blocks A'at ten intervals within the U shaped drop center channel 2 and by means of a U-bolt 5, I clamp in transverse positions over each said block a four leaf steel spring 8. The innermost of the spring leaves is bent into a hook form 'l which is adapted to hold a loop 8 of a flexible, but nonelastic cord 9 which extends diagonally and outwardly to certain tread-hoop connections I0 also in loop form: After passing through the loop I0 `the two portions 9 of the loop 8 merge at Il into a tread carrying wrapper l2 and the loops I0 grow out of this same wrapper l2 at I2 on the opposite sides of the tread hoops I3. Afxed to the tread-hoop wrapper I2 are tread ropes I4 of chemically treated istle or other suitable bre.

The secret of obtaining a serviceable, resilient non-rubber tire does not reside chieiiy in the selection of novel materials, but in the disposition and arrangement of materials already often proposed for use in connection with tires.

Thousands of eiorts to create a roadable substitute for the inflated rubber tire having thus far failed, a full disclosure of my invention should include a brief description of the essentials I supply which have been missing in proper combination in prior efforts: For example of iirst importance is the matter of comparative total weight and second the relative disposition of that weight.

I employ steel springs 6 to afford resiliency to my tire, these are of metal and metal is relatively heavy, but it will be noted that I use only ten of th'ese springs to yieldably attach 20 loops, see 9 of Fig. 1, also see loops 'l in my earlier Patent No. 1,954,214, April 10, 1934, and the amount of metal-cut 01T of the iniiated tire drop center rim at 3 off-sets the weight of these springs both as to amount of weight and also as to distance of weight location from the wheel center.

(For a comparison see typical drop center wheel rim 23 of Fig. 11, in my prior Patent No. 2,235,378, March 18, 1941.)

Having in this way supplied the third requisite, resiliency, for a roadable tire and keeping the weight down and placed not too far from the wheel cente;` I must now, without excessive weight transfer the resiliency to the periphery or outermost tread portion of the tire: That is the essential place where the resiliency must be had, but if the weight needed to obtain such resiliency were placed far outwardly from the wheel center gyroscopic and flywheel action would render the tire dangerous at high speeds and also such weight, being immediate to the tread, would give the tread concentrated instead of diffused loadings of impact at speed and lessen the tread life regardless of what materials might be employed for the tread.

This diffusing of load imparted to the tread, which I classify as another essential of a roadable tire, I obtain by employing very flexible tread hoops I3, preferably made up of laminations of hickory or plastic layers I5 cemented to layers of fabric I5 and having an outer layer of exceedingly thin spring steel II also bonded firmly toithe outer; layer of hickoryandth'e'whole. iirmly wrapped andV bonded withinand" to an" envelope I3 of fabric especially treated for Weather resistance after the fashion of treatingl marline. Also cemented to this wrapping of. the,

tread fillers I3 and over the outside of the wrapper I8 I cement a partial cover I2 wlfii'chhastheA ropes I4 sewn and cemented to. it and which iscontinuous along the entire bottom portions of the tread hoops I3, and merges into the loop cords the actual tread contactwith therroadthrough L aflexingjmember, secondly, since. the cords. 9- are flexible: theyV refuse. to carry anyl axlel loads directly downward. tov the tire tread. and the.V only way` they do impart such axle orvehicle loads is.. even-.more indirectly than byv meansof an iniiated tire,v i. e., through tension. from the upper portions of the said hoopsand only after the steel. springs have yieldablydelivered their loads to the cords 9.for transferof yieldablemtion to theflexible tread hoops.

Thereis a fifth essential for safety in any tire andthatis lateral strength, whichY I` attain by means ofthe.diagonalcrossing. of. the .cords Q,-

afterl the. manner shown .in.my; formerv patents andmy copending application, Serial No. 372,628, ledLDecember 3i, `l9i0, which maturedinto Patent .2,331,212, October 5, 1943.. In. the present case the; springs-'62 act almost,perfectlyV for vertical easy motion, while preventing lateral displacementVi. e.the. range of Avertical movement iscOmparatiVely-vastisee brtoc of Fig, 2), while the lateral movement :permitted isinnitesimal; note thatthemovement of thespringhoolt 'I from bto a swings in an outwardarc.

The` preferred arrangement for. assembling, my non-rubber tire-iis toadjust the: cords 9 in length and the spring tv in strengthV so that. when the full static load is imposed on the wheel and tire the ODHIOS SplirlgSStaketheposition indicated in Fig. 2 at a.

The fullline. position 'I of the springend or hookisl the unloaded tire position with enough initial tension to. pull .all of the springs-from their relaxedposition b.. Thisinitial tension isv put into the tiieon assemblyand it should be clearly noted'. that neither. the cords .9 nor. the springs .Ei are .part cf the .vehicle wheel-,

The wheel is. complete-.having .al hub, notv shown,

to which the disc or. spider. isdemountablymcunte ed vin conventional fashion/and a. wheel rim 2 which isthe outermost partofanyproper wheel. The. wheel including its rim isof the rigidv or nonsresilientv type. A. hub. cap is usually fitted on.tle.outside.(left hand portion .ofFig 2) while the space for the brake is on the right upper direction of Fig. 2.

Thus the tire proper includes the springs, cords and tread hoops which substitute as a whole for an inflated tire and are connected to the wheel rim by means of the U-bolts 5. c indicates the extreme deiiected position of the spring 6, such as might occur when traveling over bumps in the road at high speed and if more range of resiliency isdesired Ihave'shown in2- Fig, 5 a 4coil spring I9 as a substitute for part or all of the cord 9 and 9a and to avoid metal to metal contacts I have provided a fibre or fabric bushing 2U and at 2| I indicateailexible steel cable which may be substituted forthe cords 9 in any of the various combinations. The spring I9 is shown under extreme tension as its normal coil position would find the coils close together.

In operation it will be observed my tire is as light and resilient vertically as an inflated tire while laterally much stronger; the lateral strength being easilyjregulated by designing Whatever diagonal angles are` desired intol the tire. The chief surprise result or' triclr'inv the tire is the means by which a fineI range of increasing curve resiliency is produced inv thevertical plane and way out at thetire treadby means of a few steel springs placedso'near'the wheel center that their weight doesk notcreate` destructive ywheel action and nevertheless conventional spaceis left for brake drum and demountablewheel bolts.'

In practice if much resiliencyv is' desired' coil springs as' shown in Fig; 5 may beemployed, but should follow the rule about proximity to the wheel axis and' be placed imn'rediately` near'to hook l ofspring 6, also all conne'ctions'such as 2B shouldbe tightly'bound by adhesive tape or in someotherway to prevent'friction of partsl There areV a'great number of materials'which can be used for the cords SandV for thetreadsIII," includingminerals with semi-hard chemical bind--l ersandjplastics could afford an excellentsubstitutefor the hickory strips of the laminated llersgvbut foran'emergencygwartime' tire I have indicated.` inexpensive material such as the. well known. marline, having a tar compoundlover a grass. base', this will. pick up particlesfrom the roadto form an outside coating for the ropeslll;l or it might be desirable before the tire is run to roll it over small particles' ofmicav I4 to acquire a protective coating.

Also in assemblingY the tire it is best to have the outeror curb contacting edges of the tread` hoops extend laterally farther outward than the ends 'E ofthe cross springs of thetires. The hub cap can be designed to cover the normal positions ofthe hooks 'IQ Practice has shown that twoadvantages .stem from the separate attachment ofeach leaf spring to the wheel. rim; breakingofone or even 4two attachments allowsthetire tofunction andfthus avoids collapseandalso individual replacements can be more easily made.

Having explainedmy invention by meansof a specific embodiment it willreadilybe adaptable to wide changesiwithout departing from thespirit and teachingsof the invention and what I claim 1. .In combination witha vehiclewheel and rim. having arigid relationto each other, atire in.- cludingl leaf springs and aflexible tread. portion, cach said leaf spring attached at its. center to the said rim andtwo coil springsattached, one at eaclilend of the7 said leaf spring and iiexible cables securedto said coil springs..and'saidtreadportion and carrying the wheel loads from the said rim through the said leaf and coil springs to the radially outer portions of the said tread portion.

2. A vehicle wheel rim and flexible tire tread combination wherein leaf springs are attached at spaced intervals to the said rim and arranged transversely to the rotary plane thereof, coil springs attached to flexible cords forming a tension connection between the ends of said leaf springs and the said exible tread.

3. A wheel including a wheel rim, a tire for the said wheel having a flexible tread portion, multiple leaf springs each attached separately at its center to the said rim so that its ends extend laterally on both sides thereof and one of the said leaves of each of said springs provided With a rounded non-metallic bearing at both of its ends, a coil spring attached to each said bearing and cords leading transversely across the radial plane of the said wheel from said coil springs to the JAMES V. MARTIN. 

